Touch panels are classified into an optical type, an ultrasonic type, a capacitive type, a resistive type and the like according to the position detection method. For a resistive touch panel, such a structure is generally employed that a transparent conductive film of an upper electrode and glass with a transparent conductive layer or transparent conductive film of a lower electrode are so arranged as to face each other with a spacer interposed therebetween, and a current is passed through the upper electrode and an electric potential in the lower electrode is measured. A capacitive touch panel has as a basic structure a structure having a patterned transparent conductive layer on a base, and is used for vehicle-mount applications and the like because it has high durability and high transmittance.
The capacitive touch panel allows simultaneous multi-point input (multi-touch) and is excellent in operability, and is therefore rapidly growing in demand. On the other hand, when multi-touch occurs at two or more locations in the resistive touch panel which uses one flat plate electrode, an average electric potential thereof is detected, and a halfway point between the touched two locations is recognized as a touch point. Therefore, the conventional resistive touch panel has been considered to be unsuitable for multi-touch.
On the other hand, it has been recently proposed that multi-point input can be performed by a matrix-type resistive touch panel in which transparent conductive layers patterned in a strip form are used for both an upper electrode and a lower electrode, and arranged in a matrix form so that the pattern directions of these layers are orthogonal to each other (for example Patent Document 1). Such a matrix-type resistive touch panel receives attention because it can be produced at low costs as the required number of transparent conductive films and ICs is small in comparison with the capacitive touch panel.
In both the capacitive touch panel and the matrix-type resistive touch panel, the transparent conductive film which forms an electrode has a pattern part in which a transparent conductive layer is formed on a base and a pattern-opening part in which the transparent conductive layer is not formed on the base. Concerning the transparent conductive film in which the transparent conductive layer is patterned in this way, for example, it is proposed in Patent Document 2 that for suppressing a difference in visibility between the pattern part and the pattern-opening part of the transparent conductive film, a coating layer is provided on a surface of a substrate on which the transparent conductive layer is formed.